Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Regional Haze State Implementation Plan for the Second Implementation Period

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R01-OAR-2023-0185; FRL-11616-02-R1]</DEPDOC> <SUBJECT>Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Regional Haze State Implementation Plan for the Second Implementation Period</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA) is approving the regional haze State Implementation Plan (SIP) revision submitted by Massachusetts on July 22, 2021, and supplemented on June 15, 2022, as satisfying applicable requirements under the Clean Air Act (CAA) and EPA's Regional Haze Rule for the program's second implementation period. Massachusetts' SIP submission addresses the requirement that states must periodically revise their long-term strategies for making reasonable progress towards the national goal of preventing any future, and remedying any existing, anthropogenic impairment of visibility, including regional haze, in mandatory Class I Federal areas. The SIP submission also addresses other applicable requirements for the second implementation period of the regional haze program. The EPA is taking this action pursuant to sections 110 and 169A of the Clean Air Act. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This rule is effective on August 7, 2024. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> EPA has established a docket for this action under Docket Identification No. EPA-R01-OAR-2023-0185. All documents in the docket are listed on the <E T="03">https://www.regulations.gov</E> website. Although listed in the index, some information is not publicly available, <E T="03">i.e.,</E> CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available at <E T="03">https://www.regulations.gov</E> or at the U.S. Environmental Protection Agency, EPA Region 1 Regional Office, Air and Radiation Division, 5 Post Office Square—Suite 100, Boston, MA. EPA requests that if at all possible, you contact the contact listed in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section to schedule your inspection. The Regional Office's official hours of business are Monday through Friday, 8:30 a.m. to 4:30 p.m., excluding legal holidays and facility closures due to COVID-19. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Eric Rackauskas, Air Quality Branch, U.S. Environmental Protection Agency, EPA Region 1, 5 Post Office Square—Suite 100, (Mail code 5-MI), Boston, MA 02109-3912, tel. (617) 918-1628, email <E T="03">rackauskas.eric@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document whenever “we,” “us,” or “our” is used, we mean EPA. <HD SOURCE="HD1">Table of Contents</HD> <EXTRACT> <FP SOURCE="FP-2">I. Background and Purpose</FP> <FP SOURCE="FP-2">II. Response to Comments</FP> <FP SOURCE="FP-2">III. Final Action</FP> <FP SOURCE="FP-2">IV. Incorporation by Reference</FP> <FP SOURCE="FP-2">V. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. Background and Purpose</HD> On July 22, 2021, and supplemented on June 15, 2022, the Massachusetts Department of Environmental Protection (MassDEP) submitted a revision to its SIP to address regional haze for the second implementation period. MassDEP made this SIP submission to satisfy the requirements of the CAA's regional haze program pursuant to CAA sections 169A and 169B and 40 CFR 51.308. On January 10, 2024, the EPA published a notice of proposed rulemaking (NPRM) in which the EPA proposed to approve Massachusetts' July 22, 2021 (as supplemented on June 15, 2022), <SU>1</SU> <FTREF/> SIP submission as satisfying the regional haze requirements for the second implementation period contained in the CAA and 40 CFR 51.308. The EPA is now determining that the Massachusetts regional haze SIP submission for the second implementation period meets the applicable statutory and regulatory requirements and thus approves Massachusetts' submission into its SIP. <FTNT> <SU>1</SU>  Massachusetts submitted a letter on May 3, 2024, to clarify the intent of their June 15, 2022 supplement regarding the incorporation of the Canal permit provisions into the SIP. </FTNT> Other specific requirements of the Massachusetts submittal and the rationale for the EPA's proposed action are explained in the NPRM and will not be restated here. <HD SOURCE="HD1">II. Response to Comments</HD> In response to the NPRM, the EPA received a comment letter signed by the National Parks Conservation Association, Sierra Club, Appalachian Mountain Club, and the Coalition to Protect America's National Parks (collectively, the “Conservation Groups” or the “Groups”) and is providing responses to the comments raised in the letter. The Conservation Groups state in their comment letter that they “do not oppose EPA's proposal to approve Massachusetts' [Regional Haze] SIP Revision,” but rather “urge EPA to address the issues raised [in the comment letter] before finalizing” the approval. EPA also received a comment letter from the Mid-Atlantic/Northeast Visibility Union (MANEVU) in support of the proposed action. The specific comments may be viewed under Docket ID Number EPA-R01-OAR-2023-0185 on the <E T="03">https://www.regulations.gov</E> website. <E T="03">Comment:</E> The Conservation Groups contend that MANEVU's visibility modeling and source selection method used an inappropriately high threshold. The Conservation Groups comment that the MANEVU threshold on which Massachusetts relied (3.0 Mm <E T="51">−1</E> ) identified only two sources for a Four-Factor Analysis—Brayton Unit 4 and Canal Unit 1—and failed to select other significant sources, such as municipal waste combustors (MWCs), that have higher NO <E T="52">X</E> emissions. The Groups state that “Massachusetts should have used a lower threshold that captured a meaningful portion of in-state sources, such as a Q/d of 5 or lower, or an equivalent threshold.” As the 3.0 Mm <E T="51">−1</E> threshold identified only two sources in the entire State for a four-factor analysis, the Groups claim that Massachusetts failed to conduct a rigorous and meaningful source selection process. <E T="03">Response:</E> As explained in the NPRM, the EPA does not necessarily agree that the 3.0 inverse megameters (Mm <E T="51">−1</E> ) visibility impact is a reasonable threshold for source selection. The Regional Haze Rule recognizes that, due to the nature of regional haze visibility impairment, numerous and sometimes relatively small sources may need to be selected and evaluated for implementation of control measures to make reasonable progress. <SU>2</SU> <FTREF/> As EPA has explained, while states have discretion to choose any source selection threshold that is reasonable, “[a] state that relies on a visibility (or proxy for visibility impact) threshold to select sources for four-factor analysis should set the threshold at a level that captures a meaningful portion of the state's total contribution to visibility impairment to Class I areas.” In this case, the 3.0 Mm <E T="51">−1</E> threshold used in MANEVU Ask 2 identified only two sources in Massachusetts (and only 22 across the entire MANEVU region), indicating that it may, in some cases, be unreasonably high. But these were not the only sources Massachusetts selected for analysis. As EPA noted in the NPRM, Massachusetts considered a large set of sources that burn fuel oil throughout much of the Commonwealth and considered the four statutory factors to develop sulfur in fuel regulations that control SO <E T="52">2</E> emissions from them. <SU>3</SU> <FTREF/> Massachusetts also examined the emissions from, and the controls that apply to, its largest operating electric generating unit (EGU) and industrial/commercial/institutional boiler (ICI boiler) sources. <SU>4</SU> <FTREF/> In addition, Massachusetts examined emissions from peaking combustion turbines that have the potential to run on high electric demand days and identified existing stringent controls for such sources or equivalent alternative reductions achieved through retirements. <SU>5</SU> <FTREF/> Massachusetts also examined emissions from the municipal waste combustors (MWCs) identified by the National Park Service through the federal land manager (FLM) consultation process, and thus demonstrated that it relied upon previously EPA-approved NOx emission limits for both large and small MWCs in its long-term strategy, and reasonably explained its decision not to conduct four factor analyses at this time for the four MWCs included in the National Park Service's final list. <SU>6</SU> <FTREF/> <FTNT> <SU>2</SU>   <E T="03">See</E> Clarifications Regarding Regional Haze State Implementation Plans for the Second Implementation Period, EPA Office of Air Quality Planning and Standards, at 4 (July 8, 2021) (“2021 Clarifications Memo”). </FTNT> <FTNT> <SU>3</SU>  89 FR 1482, 1499 (January 10, 2024). </FTNT> <FTNT> <SU>4</SU>   <E T="03">Id.</E> at 1495, 1499. </FTNT> <FTNT> <SU>5</SU>   <E T="03">Id.</E> at 1496, 1499. </FTNT> <FTNT> <SU>6</SU>   <E T="03">Id.</E> at 1504; Massachusetts Regional Haze SIP Revision at 104-08. </FTNT> Furthermore, the Regional Haze Rule does not require states to consider controls for all sources, all source categories, or any or all sources in a particular source category. Rather, states have discretion to choose any source selection methodology or threshold that is reasonable, provided that the choices they make are reasonably explained. <SU> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 34k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━